WO2018043105A1

WO2018043105A1 - Gas generator

Info

Publication number: WO2018043105A1
Application number: PCT/JP2017/029272
Authority: WO
Inventors: 福井勇貴; 小林睦治
Original assignee: 株式会社ダイセル
Priority date: 2016-08-29
Filing date: 2017-08-14
Publication date: 2018-03-08
Also published as: DE112017004351T5; US10814828B2; US20190176745A1; CN109641567B; JP6930981B2; JPWO2018043105A1; KR20190039708A; KR102288663B1; CN109641567A

Abstract

The present invention is a gas generator that has a first combustion chamber, a second combustion chamber, and a plenum chamber within a housing which has a top panel, a bottom plate, and a peripheral wall portion with a gas exhaust port. The first combustion chamber is disposed on the top panel side. The second combustion chamber is disposed on the bottom plate side. The plenum chamber is disposed between the first combustion chamber and the second combustion chamber and faces the gas exhaust port. A first ignitor for igniting and burning a first gas generating agent stored within the first combustion chamber and a second ignitor for igniting and burning a second gas generating agent stored within the second combustion chamber are mounted on the bottom plate. The first combustion chamber is formed from a space which is enclosed by an inner cylinder, a first annular retainer, and the top plate. The plenum chamber is formed from a space which is enclosed by the inner cylinder, the first annular retainer, the housing peripheral wall portion with the gas exhaust port, and a second annular retainer. The second combustion chamber is formed from a space which is enclosed by the inner cylinder, the second annular retainer, the housing peripheral wall portion, and the bottom plate.

Description

Gas generator

This invention relates to the gas generator which can be used for the airbag apparatus of a motor vehicle.

BACKGROUND ART A gas generator used for an air bag apparatus contains necessary parts and the like in a housing. As the shape of the housing, a cylinder shape and a disk shape are known, and a gas generator in which two combustion chambers are vertically separated is known.

In FIG. 1 of US Pat. No. 6,485,051 B, the inside of the housing 1 is divided into an upper combustion chamber 3 and a lower combustion chamber 4 by a partition wall 5, and each combustion chamber is filled with a gas generating agent 6, and an igniter. 8 and 9 disclose a dual type gas generator in which the gas generating agent 6 is individually ignited. The igniters 8 and 9 are fixed to the lower lid 17 side, and the igniter 8 is attached to a cylindrical casing 18 extending from the lower lid 17.

DISCLOSURE OF THE INVENTION A first aspect of the present invention (hereinafter referred to as “first aspect”) includes a top plate, a bottom plate, and a housing having a peripheral wall portion having a gas discharge port,
A first combustion chamber formed between a first annular retainer disposed in the housing and the top plate;
A second combustion chamber formed between a second annular retainer disposed in the housing and the bottom plate;
A plenum chamber that communicates with the gas outlet disposed between the first combustion chamber and the second combustion chamber;
A first igniter fixed to the bottom plate and configured to ignite and burn the first gas generating agent in the first combustion chamber; and a second igniter disposed in the second combustion chamber, facing the second combustion chamber. A second igniter that ignites and burns,
It is disposed in the housing, the first end opening surrounds the first igniter, the second end opening is located on the top plate side, and a transfer hole is formed at a position facing the first combustion chamber. Having an inner cylinder,
The first annular retainer has a first annular bottom surface portion having a first communication hole, and a first inner peripheral edge portion of the first annular bottom surface portion is brought into contact with a peripheral wall portion of the inner cylinder, and the first communication The first combustion chamber and the plenum chamber communicate with each other through a hole,
The second annular retainer has a second annular bottom surface portion having a second communication hole, a second inner peripheral edge portion of the second annular bottom surface portion is in contact with a peripheral wall portion of the inner cylinder, and the second communication A gas generator in which the second combustion chamber and the plenum chamber are communicated with each other through a hole.

According to a second aspect of the present invention (hereinafter referred to as “second aspect”), a top plate, a bottom plate, and a housing having a peripheral wall portion having a gas discharge port are arranged on the top plate side. 1 combustion chamber, a second combustion chamber disposed on the bottom plate side, and a plenum chamber facing the gas discharge port disposed between the first combustion chamber and the second combustion chamber,
The bottom plate has a first igniter for igniting and burning the first gas generating agent accommodated in the first combustion chamber, and an ignition for burning the second gas generating agent accommodated in the second combustion chamber. The second igniter is installed,
In the first igniter, the first end opening surrounds the first igniter, the second end opening is located on the top plate side, and is in a position facing the first combustion chamber. Arranged to communicate with the first combustion chamber via an inner cylinder having a hole;
The second igniter is disposed facing the second combustion chamber;
The first annular retainer has a first annular bottom surface portion having a first communication hole, and a first annular outer wall portion extended in the top plate direction from a first outer peripheral edge portion of the first annular bottom surface portion. The first annular retainer is configured such that a first inner peripheral edge of the first annular bottom surface is in contact with a peripheral wall of the inner cylinder, and the first annular outer wall is between the housing peripheral wall. In a state of being spaced apart, the annular end surface in the axial direction of the first annular outer wall portion is fitted into the inner cylinder so as to be in contact with the top plate,
The second annular retainer has a second annular bottom surface portion having a second communication hole, and a second annular outer wall portion extended in the top plate direction from the second outer peripheral edge portion of the second annular bottom surface portion. The second annular retainer is configured such that the second inner peripheral edge of the second annular bottom surface is in contact with the peripheral wall of the inner cylinder, and the second annular outer wall is in contact with the peripheral wall of the housing. Is fitted into the inner cylinder so that
The first combustion chamber comprises a space surrounded by the inner cylinder, the first annular retainer, and the top plate;
The plenum chamber is composed of a space surrounded by the inner cylinder, the first annular retainer, a housing peripheral wall having the gas discharge port, and the second annular retainer;
A gas generator is provided in which the second combustion chamber is composed of a space surrounded by the inner cylinder, the second annular retainer, the housing peripheral wall, and the housing bottom plate.

The present invention will be more fully understood from the following detailed description and the accompanying drawings. However, these are merely for the purpose of explanation and are not intended to limit the present invention.

FIG. 1 is an axial sectional view of an embodiment of a gas generator of the present invention. FIG. 2 is an axial cross-sectional view of an embodiment in which a guide plate is added to the first communication hole of the first annular retainer of the gas generator of FIG. FIG. 3 is an axial cross-sectional view of an embodiment in which the arrangement of the first communication hole of the first annular retainer and the second communication hole of the second annular retainer is different from the gas generator of FIG. 1. FIG. 4 is an axial cross-sectional view of an embodiment using an annular filter different from the annular filter used in the gas generator of FIG. 5A is an axial sectional view of another embodiment of the gas generator of the present invention in FIG. 5A, and FIG. 5B is an axial sectional view of the inner cylinder in FIG. FIG. 6 is an axial sectional view of still another embodiment of the gas generator of the present invention. FIG. 7 is an axial cross-sectional view of an embodiment in which the shapes of the first annular retainer and the second annular retainer are different from the gas generator of FIG. 6.

DETAILED DESCRIPTION OF THE INVENTION In the gas generator of US 6,485,051 B, a cushion 25 is arranged on the partition wall 5 and serves both as absorption of shock to the gas generating agent 6 and thermal insulation, but has a large combustion heat. In the case of a gas generating agent, the thermal insulation effect is not sufficient. Moreover, since the filter 7 is arrange | positioned in both the upper combustion chamber 3 and the lower combustion chamber 4, the filter amount increases and the whole mass is increased.

The present invention has a structure in which the heat generated by the combustion of the first gas generating agent in the first combustion chamber is not easily transmitted to the gas generating agent in the second combustion chamber, and each gas generating agent can be reliably ignited independently. A gas generator is provided.

In the gas generator according to the present invention, the first combustion chamber, the plenum chamber facing the gas discharge port, and the second combustion chamber are separated into three chambers in order from the top plate side between the top plate and the bottom plate of the housing. It is what has been. The first combustion chamber contains the first gas generating agent and the second combustion chamber contains the second gas generating agent, but at least the gas generating agent is not arranged in the plenum chamber, and the air It is an existing space.

In the gas generator of the present invention, the first igniter operates first to combust the first gas generating agent in the first combustion chamber first, and the second igniter operates slightly after a short delay to operate the second combustion chamber. The second gas generating agent can be combusted. Alternatively, only the first igniter can be operated to burn only the first gas generating agent (the second gas generating agent can be kept in a non-burning state).

The combustion gas generated in the first combustion chamber enters the plenum chamber from the first communication hole, and is then discharged from the gas discharge port. The combustion gas generated in the second combustion chamber enters the plenum chamber from the second communication hole. After that, it is discharged from the gas outlet. At this time, if there is no plenum chamber, the heat caused by the combustion gas and residue generated in the first combustion chamber is transferred to the second combustion chamber via the partition wall (retainer).

However, in the present invention, even when the first combustion chamber becomes hot due to combustion of the first gas generating agent and the first annular retainer becomes hot, the plenum chamber is interposed between the first annular retainer and the second annular retainer. Therefore, the temperature rise of the second annular retainer is suppressed by the heat insulating action of air. Further, when the combustion gas in the first combustion chamber enters the plenum chamber from the first communication hole, the combustion gas is quickly discharged from the gas discharge port while the temperature is lowered from the first combustion chamber, so that the second annular retainer Temperature rise is suppressed. For this reason, the second gas generating agent in the second combustion chamber is prevented from being ignited and burned by the heat generated by the first gas generating agent in the first combustion chamber being ignited and burned. Independent ignition of each generator is ensured.

The housing, inner cylinder, first annular retainer and second annular retainer used in the gas generator of the present invention are all made of stainless steel, iron, or the like. A gas generating agent that functions as a known transfer agent or transfer agent can also be accommodated inside the inner cylinder. The heat transfer hole of the inner cylinder is formed at a position facing the first combustion chamber. The heat transfer hole can be formed in the peripheral wall portion of the inner cylinder facing the first combustion chamber when the second end opening of the inner cylinder is in contact with the top plate, and the second end of the inner cylinder When the opening is not in contact with the top plate and there is a gap between the second end opening of the inner cylinder and the top plate, the gap faces the first combustion chamber, so the gap is transferred to the heat. It will function as a hole.

The gas outlet on the peripheral wall of the housing is closed from the inside with a metal seal tape to prevent moisture.

The hole of the first annular retainer and the hole of the second annular retainer do not have to be in the center portion, and may be in an offset position, but have a shape and size that can be fitted into the inner cylinder. is there. The first annular retainer and the second annular retainer adjust the inner diameter (the diameter of the hole), the outer diameter and height of the first annular outer wall portion and the second annular outer wall portion, and the like. It is attached by being press-fitted into the housing peripheral wall.

The first annular retainer may have a first annular inner wall extending from the first inner peripheral edge (the peripheral edge of the hole) in the same direction as the first annular outer wall. When the first annular inner wall portion is provided, the first annular inner wall portion comes into contact with the inner cylinder. The second annular retainer may have a second annular inner wall extending from the second inner peripheral edge (periphery of the hole) in the same direction as the second annular outer wall. When the second annular inner wall portion is provided, the second annular inner wall portion comes into contact with the inner cylinder.

The first igniter and the second igniter are both used in a known gas generator, and are attached to one hole or two holes formed in the housing bottom plate.

In the gas generator according to a preferred aspect of the present invention, the housing has a diffuser shell composed of a first peripheral wall portion having a top plate and a gas discharge port, and a closure shell composed of a bottom plate and a second peripheral wall portion,
The outer surface of the second peripheral wall portion of the closure shell is brought into contact with and integrated with the inner surface of the first peripheral wall portion of the diffuser shell, so that the closure shell first facing the top plate side of the diffuser shell. An annular step surface composed of an annular end surface of the two peripheral walls is formed,
The first annular retainer has a first flange portion extending radially outward from a tip end of the first annular outer wall portion, and the first flange portion is in contact with the top plate. ,
The second annular retainer has a second flange portion extending radially outward from the second annular outer wall portion, and the second flange portion is in contact with the annular step surface.

In the gas generator according to this aspect, the housing is a combination of a diffuser shell and a closure shell, and the first peripheral wall portion of the diffuser shell and the second peripheral wall of the closure shell are fitted by fitting the closure shell inside the diffuser shell. An annular step surface composed of a portion is formed. The first annular retainer has a first flange portion on the first annular outer wall portion, the second annular retainer has a second flange portion on the second annular outer wall portion, and the second flange portion is on the annular step surface. Abutment is supported.

Furthermore, in the gas generator according to a preferred aspect of the present invention, the inner cylinder has an inner diameter and an outer diameter that decrease from the bottom plate side toward the top plate side.

The inner and outer diameters of the inner cylinder include those that are continuously reduced and those that are gradually reduced. If the inner cylinder has the shape described above, when the first igniter is activated and a flame or the like is generated, the rate of rise of the flame or the like increases as the distance from the top plate increases, and the rate of discharge of the flame or the like into the first combustion chamber Therefore, the ignitability of the first gas generating agent located far from the first igniter is enhanced. In addition, when the transfer charge is ignited and combusted by the flame generated by the operation of the first igniter and a combustion product (flame, combustion gas, etc.) is generated, the rate of increase of the combustion product increases as it gets closer to the top plate. In addition, since the discharge rate of the combustion products into the first combustion chamber is also increased, the ignitability of the first gas generating agent is improved.

Furthermore, in the gas generator according to a preferred aspect of the present invention, the inner diameter and the outer diameter of the inner cylinder are gradually reduced from the bottom plate side toward the top plate side,
A hole of the first annular retainer is fitted into the first annular step portion closest to the top plate side so as to be prevented from moving to the bottom plate side, and the second closest from the top plate side. It is arrange | positioned so that the movement to the said baseplate side may be prevented by the hole of the said 2nd annular retainer being engage | inserted by the 2 annular step part.

Thus, in order from the housing top plate, the first annular retainer is fitted into the first annular stepped portion, and the second annular retainer is fitted into the second annular stepped portion, so that each is supported in the axial direction. It does not move to the bottom plate side. Furthermore, the effect of improving the ignitability of the first gas generating agent is obtained.

Furthermore, in the gas generator according to a preferred aspect of the present invention, the second communication hole of the second annular retainer is closed with a closing member from the plenum chamber side,
The first communication hole of the first annular retainer and the second communication hole of the second annular retainer are arranged so as not to overlap in the axial direction.

The sealing member is preferably a seal tape made of a combination of a base material such as stainless steel and an adhesive. When the axial positions of the first communication hole and the second communication hole do not overlap, the combustion gas discharged from the first communication hole does not directly hit the blocking member of the second communication hole. can do.

Furthermore, in the gas generator according to a preferred aspect of the present invention, the second communication hole of the second annular retainer is closed with a closing member from the plenum chamber side, and does not overlap the second igniter in the axial direction. Are arranged in such a way.

It is preferable that the closing member that closes the second communication hole is cleaved when the second gas generating agent in the second combustion chamber burns to generate combustion gas and the pressure in the second combustion chamber rises. Since the pressure in the second combustion chamber rises to a certain level when it is cleaved in this way, it is preferable because the ignitability of the entire second gas generating agent is improved.

In this aspect, since the second communication hole and the second igniter do not overlap in the axial direction, a flame generated from the second igniter directly collides with the second communication hole and damages the blocking member. Or being cleaved. Therefore, in order to avoid the state in which the second communication hole is opened at the initial stage where the second gas generating agent burns, the combustion performance of the second gas generating agent can be maintained.

Furthermore, in the gas generator of the first aspect, preferably, an annular filter is disposed in the plenum chamber,
The first annular end surface of the annular filter is in contact with a portion of the first annular bottom surface portion that does not have the first communication hole, and the second annular end surface is in a portion of the second annular bottom surface portion that does not have the second communication hole. Abutted,
At least a portion where the first annular bottom surface portion and the second annular bottom surface portion directly face each other is formed.

Thus, since the annular filter is only in partial contact with the first annular bottom surface portion and the second annular bottom surface portion and has a small contact area, heat transfer through the annular filter is suppressed. In the plenum chamber, a portion where the first annular bottom surface portion and the second annular bottom surface portion are directly opposed to each other is formed. This means that an object that physically connects the annular bottom surface portion and the second annular bottom surface portion is not disposed.

Furthermore, in the gas generator of the second aspect, preferably, an annular filter is disposed in the plenum chamber,
In the annular filter, the first annular end surface on the top plate side is in contact with a portion of the first annular bottom surface portion of the first annular retainer where there is no first communication hole, and the second annular end surface on the bottom plate side is a second annular surface. The retainer is disposed in contact with a portion of the second annular bottom surface portion of the retainer where there is no second communication hole, and a part of the outer peripheral surface is disposed in contact with the second annular outer wall portion.

The gas generator of this aspect is one in which an annular filter is arranged in the plenum chamber. By arranging the annular filter only in the plenum chamber in this way, the amount of filter can be reduced as compared with the filter of the gas generator of FIG. 1 of US Pat. No. 6,485,051B.

Furthermore, in a preferred aspect of the present invention, an annular filter is disposed in the plenum chamber.
In the annular filter, the first annular end surface on the top plate side has a first annular projection, and the second annular end surface on the bottom plate side has a second annular projection,
The first annular protrusion is brought into contact with a portion of the first annular retainer where the first annular bottom surface portion does not have the first communication hole, and the second annular protrusion is a second communication hole of the second annular bottom surface portion of the second annular retainer. And a part of the outer peripheral surface is placed in contact with the second annular outer wall.

Each of the first annular protrusion and the second annular protrusion of the annular filter may be one or more. For example, a total of two annular protrusions are formed on the inner peripheral edge side and the outer peripheral edge side of the annular filter, and further, one annular protrusion is formed at an intermediate position, and a total of three annular protrusions are formed. It can be made into a form. Even when three annular protrusions are used, the area can be made the same as that of the two annular protrusions by narrowing the width. An annular groove is formed between the annular protrusions and does not contact the first annular retainer and the second annular retainer.

When the temperature in the first combustion chamber rises and the temperature of the first annular retainer rises, the temperature of the second annular retainer also rises via the annular filter. However, by reducing the contact area between the first annular retainer and the second annular retainer and the annular filter as in this aspect, heat transfer from the first annular retainer to the second annular retainer via the annular filter as described above. Is suppressed.

Furthermore, in the gas generator according to a preferred aspect of the present invention, the axial interval between the first annular retainer and the second annular retainer is larger in the interval (w1) closer to the housing peripheral wall and closer to the inner cylinder. The interval (w2) is smaller (w1> w2), an annular filter is disposed in the portion where the interval is w1, and the first communication hole and the second communication hole are provided in the portion where the interval is w2. Is formed.

In the gas generator of this aspect, the interval (w1) between the first annular retainer and the second annular retainer is increased between the portions where the annular filter is disposed, and the interval (w2) between the portions where the annular filter is not disposed. It is a small one. Thereby, the volume of a 1st combustion chamber and a 2nd combustion chamber can be increased, without reducing the amount of annular filters. In addition, the space | interval (w2) of the part by which the annular filter is not arrange | positioned may increase continuously from the inner cylinder side to the housing surrounding wall part side.

In the gas generator of the present invention, heat generated by combustion of the first gas generating agent in the first combustion chamber is difficult to be transmitted to the second gas generating agent in the second combustion chamber. Independent ignition of the two gas generants is reliably performed.

The gas generator of the present invention can be used as a gas generator for an airbag device mounted on an automobile.

Embodiments of the Invention (1) Gas Generator of FIG. 1 The gas generator 1 of FIG. 1 includes a diffuser shell 11 comprising a top plate 12 and a first peripheral wall portion 13 having a gas discharge port 14, a bottom plate 21, and a first plate. The housing 10 is made of a closure shell 20 made up of two circumferential walls 22. The diffuser shell 11 has a flange portion 15 at the distal end portion of the first peripheral wall portion 13. The outer surface of the second peripheral wall portion 22 of the closure shell 20 is brought into contact with the inner surface of the first peripheral wall portion 13 of the diffuser shell 11 and is welded and integrated at the contact portion. The annular end surface 23 of the second peripheral wall portion 22 of the closure shell 20 is an annular step surface continuing from the first peripheral wall portion 13 in a state of facing the top plate 12 side.

In the housing 10, the first combustion chamber 30 disposed on the top plate 12 side, the second combustion chamber 50 disposed on the bottom plate 21 side, and the first combustion chamber 30 and the second combustion chamber 50 are disposed. A plenum chamber 40 facing the gas outlet 14 formed.

The bottom plate 21 of the closure shell 20 has a first igniter 32 for igniting and burning the first gas generating agent 31 accommodated in the first combustion chamber 30 and a second igniter accommodated in the second combustion chamber 50. A second igniter 52 for igniting and burning the gas generating agent 51 is attached.

The first igniter 32 is protruded radially inward from the first cylindrical wall 24a protruding in the axis X direction (top plate 12 direction) from the hole formed in the bottom plate 21, and the first cylindrical wall 24a. It is fixed to the first annular wall 25a via the first resin portion 26a. The first cylindrical wall 24a and the first annular wall 25a function as a known metal collar. Instead of the first cylindrical wall 24a and the first annular wall 25a, the first cylindrical wall 24a and the first annular wall 25a One having a metal collar corresponding to one annular wall 25a may be fixed to the hole.

The second igniter 52 protrudes radially inward from the second cylindrical wall 24b protruding from the hole formed in the bottom plate 21 in the axis X direction (top plate 12 direction) and the second cylindrical wall 24b. It is fixed to the second annular wall 25b via the second resin portion 26b. The second cylindrical wall 24b and the second annular wall 25b function as a known metal collar. Instead of the second cylindrical wall 24b and the second annular wall 25b, the second cylindrical wall 24b and the second annular wall 25b are provided. A metal collar corresponding to the two annular walls 25b may be fixed in the hole. The second igniter 52 is disposed facing the second combustion chamber 50. The first igniter 32 and the second igniter 52 are both arranged at positions eccentric from the axis X.

An inner cylinder 60 is attached around the first igniter 32. A plurality of heat transfer holes 64 are formed at equal intervals in the circumferential direction on the peripheral wall 63 on the second end opening side (second annular end surface 62 side) on the top plate 12 side of the inner cylinder 60. . The inside of the inner cylinder 60 and the first combustion chamber 30 are communicated with each other through a heat transfer hole 64. The peripheral wall portion 63 on the first end opening side (the first annular end surface 61 side) on the bottom plate 21 side of the inner cylinder 60 has a reduced diameter portion 65, and the reduced diameter portion 65 contacts the first resin portion 26a. It is touched. The inner cylinder 60 has an enlarged diameter part whose diameter is enlarged from the reduced diameter part 65 to the bottom plate 21 side, and the enlarged diameter part surrounds the first cylindrical wall 24a to the first cylindrical wall 24a. The reduced diameter portion 65 is fixed by being press-fitted into the first resin portion 26a. The first annular end surface 61 of the inner cylinder 60 is in contact with the bottom plate 21, and the second annular end surface 62 is in contact with the top plate 12. When the second annular end surface 62 is not in contact with the top plate 12 and there is a gap between the second annular end surface 62 and the top plate 12, the gap serves as a heat transfer hole. It is not necessary to form a heat transfer hole. The internal space 66 of the inner cylinder 60 is filled with a known explosive charge (not shown).

The first combustion chamber 30, the plenum chamber 40, and the second combustion chamber 50 are partitioned in the axial direction and the radial direction by a combination of the housing 10, the inner cylinder 60, the first annular retainer 70, and the second annular retainer 80.

The first annular retainer 70 includes a first annular bottom surface portion 71 having a plurality of first communication holes 72 penetrating in the thickness direction, a first inner peripheral edge portion and a first outer peripheral edge portion of the first annular bottom surface portion 71. A first annular inner wall portion 73 and a first annular outer wall portion 74 each extending in the same direction are provided. Furthermore, the front-end | tip part of the 1st cyclic | annular outer wall part 74 has the 1st flange part 75 extended to the radial direction outer side (1st surrounding wall part 13 side). The hole 71a of the first annular bottom portion 71 is eccentric from the center (eccentric hole 71a).

The first annular retainer 70 is fitted into the inner cylinder 60 in the eccentric hole 71a. In the first annular retainer 70, the first annular inner wall portion 73 is in contact with the peripheral wall portion 63 of the inner cylinder 60, and the first annular outer wall portion 74 is spaced from the first peripheral wall portion 13 (gas discharge port 14). The first flange portion 75 is in contact with the top plate 12 in the state of being placed. A guide plate 77 as shown in FIG. 2 can be attached to the plurality of first communication holes 72 of the first annular retainer 70 in order to control the flow direction of the combustion gas. The guide plate 77 can be formed in the same manner as the guide plate shown in FIG. 3 of Japanese Patent Application Laid-Open No. 2010-264773, and the gas generated from the first combustion chamber 30 is radiated from the radius of the plenum chamber 40. It fulfills the function of flowing outward in the direction.

The second annular retainer 80 includes a second annular bottom surface portion 81 having a plurality of second communication holes 82 penetrating in the thickness direction, a second inner peripheral edge portion and a second outer peripheral edge portion of the second annular bottom surface portion 81. A second annular inner wall portion 83 and a second annular outer wall portion 84 each extending in the same direction are provided. Furthermore, the front-end | tip part of the 2nd annular outer wall part 84 has the 2nd flange part 85 extended to the radial direction outer side (1st surrounding wall part 13 side). The plurality of second communication holes 82 are closed by a stainless steel seal tape 87 attached from the plenum chamber 40 side. In the embodiment of FIG. 1, the seal tape 87 is affixed to the entire surface of the second annular retainer 80 on the plenum chamber 40 side, but may be affixed only to a portion where the second communication hole 82 is present. The hole 81a of the second annular bottom surface portion 81 is eccentric from the center (eccentric hole 81a).

The second annular retainer 80 is fitted into the inner cylinder 60 in the eccentric hole 81a. In the second annular retainer 80, the second annular inner wall 83 is in contact with the peripheral wall 63 of the inner cylinder 60, the second annular outer wall 84 is in contact with the second peripheral wall 22, and the second flange 85 is annular. It is in contact with the end face 23.

An annular filter 90 for filtering and cooling the combustion gas is disposed at a position near the first peripheral wall portion 13 of the plenum chamber 40. In the annular filter 90, the first annular end surface 91 on the top plate 12 side is in contact with a portion of the first annular bottom surface 71 of the first annular retainer 70 where the first communication hole 72 is not provided, and the second annular end surface on the bottom plate 21 side. 92 is in contact with a portion of the second annular bottom surface portion 81 of the second annular retainer 80 where the second communication hole 82 is absent. Since the annular filter 90 is in contact with only a part of the first annular end surface 91 and the second annular end surface 92 and has a small contact area, the transmission from the first annular end surface 91 to the second annular end surface 92 via the annular filter 90 is performed. Heat is suppressed. In other words, a directly opposed portion is formed between the first annular end surface 91 and the second annular end surface 92. Nothing is arranged in a portion where the first annular end surface 91 and the second annular end surface 92 are directly opposed (between both annular end surfaces). There is a gap between the inner peripheral surface 93 of the annular filter 90 and the peripheral wall portion 63 of the inner cylinder 60, and a part of the outer peripheral surface 94 is in contact with the second annular outer wall portion 84 of the second annular retainer 80. There is a gap between the outer peripheral surface 94 of the annular filter 90 and the first peripheral wall portion 13.

The first combustion chamber 30 is composed of a space surrounded by the inner cylinder 60, the first annular retainer 70 and the top plate 12. The plenum chamber 40 includes a space surrounded by the inner cylinder 60, the first annular retainer 70, the first peripheral wall portion 13 having the gas discharge port 14, and the second annular retainer 80. The second combustion chamber 50 includes a space surrounded by the inner cylinder 60, the second annular retainer 80, the second peripheral wall portion 22, and the bottom plate 21. The first combustion chamber 30 and the plenum chamber 40 communicate with each other through a first communication hole 72, the second combustion chamber 50 and the plenum chamber 40 communicate with each other through a second communication hole 82, and the plenum chamber 40 faces the gas discharge port 14. Yes.

Next, the operation when the gas generator 1 shown in FIG. 1 is used in an automobile airbag device will be described. In the following, an embodiment in which the first igniter 32 operates first and the second igniter 52 operates slightly later will be described.

When an automobile collision accident occurs, the first igniter 32 is quickly activated to ignite and burn the transfer charge filled in the inner space 66 of the inner cylinder 60, and to produce a combustion product containing flame and combustion gas. generate. Combustion products enter the first combustion chamber 30 through the transfer holes 64 and ignite and combust the first gas generating agent 31 to generate combustion gas. Combustion gas generated in the first combustion chamber 30 enters the plenum chamber 40 through the first communication hole 72, is cooled and filtered by passing through the annular filter 90, and then breaks the seal tape that closes the gas discharge port 14. Then, the air bag is discharged out of the housing 10 to inflate the airbag.

The second igniter 52 is operated slightly after the operation of the first igniter 32, and the second gas generating agent 51 in the second combustion chamber 50 is ignited and combusted to generate combustion gas. The combustion gas generated in the second combustion chamber 50 breaks the seal tape 87 and enters the plenum chamber 40 through the second communication hole 82, and is cooled and filtered by passing through the annular filter 90. The air bag is further inflated by being discharged from the discharge port 14.

In such an operation process, even when the first combustion chamber 30 becomes hot due to combustion of the first gas generating agent 31 and the first annular retainer 70 becomes hot, the first annular retainer 70 and the second annular retainer 70 are heated. Since there is a plenum chamber 40 between 80, the temperature rise of the second annular retainer 80 is suppressed by the heat insulating action of air. Further, when the combustion gas in the first combustion chamber 30 enters the plenum chamber 40 from the first communication hole 72, the seal tape 87 attached from the plenum chamber 40 side is not broken, and the combustion gas is not in the plenum chamber. 40 moves to the annular filter 90 side. At this time, the combustion gas is discharged from the gas discharge port 14 through the annular filter 90 while the temperature is lowered from the inside of the first combustion chamber 30, so that the temperature rise of the second annular retainer 80 is suppressed. Therefore, the second gas generating agent 51 in the second combustion chamber 50 is prevented from being ignited and combusted by the heat generated by the first gas generating agent 31 in the first combustion chamber 30 being ignited and burned. Independent ignition of the first igniter 32 and the second igniter 52 is reliably performed. In addition, by forcibly directing the combustion gas to the filter 90 by the guide plate 77 as shown in FIG. 2, it is possible to avoid the seal tape 87 from being affected by the pressure or temperature of the gas.

(2) Gas Generator of FIG. 3 The gas generator 1A of FIG. 3 includes the first communication hole 72 of the first annular retainer 70 and the second communication hole 82 of the second annular retainer 80 in the gas generator 1 of FIG. The gas generator 1 is the same as that shown in FIG. 1 except that the formation position in the radial direction is changed.

The first communication hole 72 of the first annular retainer 70 and the second communication hole 82 of the second annular retainer 80 are formed so as not to overlap each other in the axis X direction. The second communication hole 82 of the second annular retainer 80 is closed from the plenum chamber 40 side by a closing member (seal tape) 87 and is arranged so as not to overlap the second igniter 52 in the axial direction.

When the combustion gas in the first combustion chamber 30 enters the plenum chamber 40 from the first communication hole 72, the gas generator 1 </ b> A shown in FIG. 3 has the second annular retainer 80 without the second communication hole 82. After colliding with the bottom surface portion 81, the direction is changed, and it is cooled and filtered by passing through the annular filter 90. Thereafter, the airbag is discharged from the gas outlet 14 to inflate the airbag. The second communication hole 82 is preferably formed radially inward of the first communication hole 72.

As described above, the seal tape 87 attached from the plenum chamber 40 side is not broken, but the combustion gas ejected from the first communication hole 72 directly collides with the seal tape 87 covering the second communication hole 82. By preventing this, the strength of the seal tape 87 is prevented from decreasing before the second igniter 52 is activated.

The flame generated by the operation of the second igniter 52 is diffused after colliding with the second annular bottom surface portion 81 of the second annular retainer 80 having no second communication hole 82, and the second gas in the second combustion chamber 50 is diffused. The generating agent 51 is ignited and burned. When the pressure of the second combustion chamber 50 is sufficiently increased by the ignition combustion of the second gas generating agent 51 (that is, when the pressure of the second combustion chamber 50 is increased as designed), the seal tape 87 is cleaved and the second pressure is increased. Since the two communication holes 82 are opened, the combustion of the second gas generating agent 51 is stabilized. That is, the seal tape 87 is not cleaved by the combustion product from the second igniter 52. At this time, if the seal tape 87 is susceptible to the combustion gas from the first combustion chamber 30 flowing into the plenum chamber 40 or the operation of the second igniter 52, the pressure in the second combustion chamber 50 is as designed. There is a possibility that the seal tape 87 is cleaved before it rises, and the combustion of the entire second gas generating agent 51 may be delayed, but in this embodiment, the pressure in the second combustion chamber 50 rises as designed. Thus, the seal tape 87 is cleaved. In the case of the gas generator 1 in FIG. 1, the first communication hole 72 and the second communication hole 82 of the second annular retainer 80 are overlapped with each other in the axial X direction. If the strength is increased by increasing the thickness, the strength of the seal tape 87 can be prevented from being lowered by the combustion gas from the first combustion chamber 30 flowing into the plenum chamber 40. At that time, the required design internal pressure for increasing the strength of the seal tape 87 and causing the second gas generating agent 51 to be cleaved is (the maximum internal pressure generated in the first combustion chamber 30) <(the second combustion chamber 50). The maximum internal pressure generated by

(3) Gas Generator in FIG. 4 The gas generator 1B in FIG. 4 is different from the gas generator 1 in FIG. 1 in the shape of the annular filter, and the arrangement of the first annular retainer and the second annular retainer and the annular filter. The gas generator 1 is the same as that shown in FIG. 1 except for the state. Also in the gas generator 1B of FIG. 4, the first communication hole 72 and the second communication hole 82 can be prevented from overlapping in the axis X direction, similarly to the gas generator 1A of FIG. 3.

The annular filter 190 has a first annular end face 191a on the inner peripheral face 193 side and a first annular outer protrusion 191b on the outer peripheral face 194 side. A first annular recess 191c is formed between the one annular inner protrusion 191a and the first annular outer protrusion 191b. Further, the annular filter 190 has a second annular end face 192 on the bottom plate 21 side having a second annular inner protrusion 192a on the inner peripheral face 193 side, and a second annular outer protrusion 192b on the outer peripheral face 194 side. A second annular recess 192c is formed between the two annular inner protrusions 192a and the second annular outer protrusion 192b.

The first annular end surface 191 of the annular filter 190 is brought into contact with a portion where the first annular inner protrusion 191a and the first annular outer protrusion 191b do not have the first communication hole 72 of the first annular bottom surface portion 71 of the first annular retainer 70. ing. There is a gap between the first annular recess 191c and the first annular bottom surface 71. The second annular end surface 192 of the annular filter 190 is brought into contact with a portion where the second annular inner protrusion 192a and the second annular outer protrusion 192b do not have the second communication hole 82 of the second annular bottom surface portion 81 of the second annular retainer 80. ing. There is a gap between the second annular recess 192c and the second annular bottom surface portion 81. 4 is compared with the gas generator 1 of FIG. 1 and the gas generator 1A of FIG. 3, the contact area of the annular filter 190, the 1st annular retainer 70, and the 2nd annular retainer 80 is compared with the gas generator 1B of FIG. Is getting smaller.

When the temperature in the first combustion chamber 30 rises and the temperature of the first annular retainer 70 also rises, the temperature of the second annular retainer 80 also rises via the annular filter 190 that is in contact with the first annular bottom surface portion 71. To do. However, by reducing the contact area between the annular filter 190, the first annular retainer 70, and the second annular retainer 80 as in this embodiment, the first annular retainer 70 via the annular filter 190 as described above can be reduced. Heat transfer to the second annular retainer 80 is suppressed. For this reason, in order to maintain the independent ignition of the 1st gas generating agent 31 and the 2nd gas generating agent 51, it is more preferable.

(4) Gas Generator in FIG. 5 The gas generator 1C in FIG. 5 (a) differs from the gas generator 1 in FIG. 1 in the shape of the inner cylinder, and the first annular retainer and the second annular retainer. It is the same as the gas generator 1 of FIG. 1 except that the arrangement state of the cylinders is different. In the gas generator 1C of FIG. 5 (a), the first communication hole 72 and the second communication hole 82 can be prevented from overlapping in the direction of the axis X in the same manner as the gas generator 1A of FIG. An annular filter 190 shown in FIG. 4 can also be used.

In the gas generator 1C of FIG. 5A, the inner diameter and the outer diameter of the inner cylinder 160 gradually decrease from the first annular end surface 168a on the bottom plate 21 side toward the second annular end surface 168b on the top plate 12 side. ing. As shown in FIG. 5B, the inner cylinder 160 has a first cylinder portion 161 having the largest inner diameter and outer diameter, and a second largest inner diameter and outer diameter in order from the bottom plate 21 side to the top plate 12 side. It has a second cylindrical portion 162, a third cylindrical portion 163 having the largest inner diameter and outer diameter, and a fourth cylindrical portion 164 having the smallest inner diameter and outer diameter. Between the first tube portion 161 and the second tube portion 162, there is a third annular inclined surface portion 165, and between the second tube portion 162 and the third tube portion 163, there is a second annular inclined surface portion 166, A first annular inclined surface portion 167 is provided between the third tube portion 163 and the fourth tube portion 164. The fourth cylinder portion 164 has a plurality of heat transfer holes 169 formed at equal intervals in the circumferential direction.

The inner cylinder 160 is fixed by press-fitting the first cylinder part 161 into the first cylindrical wall 24a and press-fitting the second cylinder part 162 into the first resin part 26a. The first annular end surface 168 a is in contact with the bottom plate 21, and the second annular end surface 168 b is in contact with the top plate 12. In the second annular retainer 80, the second annular inner wall portion 83 is in contact with the third cylindrical portion 163, and the boundary portion between the second annular bottom surface portion 81 and the second annular inner wall portion 83 is the second annular inclined surface portion (first portion). By being in contact with the two annular step portions 166, movement toward the bottom plate 21 side is prevented. In the first annular retainer 70, the first annular inner wall 73 is in contact with the fourth cylindrical portion 164, and the boundary portion between the first annular bottom surface 71 and the first annular inner wall 73 is a first annular inclined surface portion (first (1 annular step portion) 167 abuts against movement toward the bottom plate 21 side.

As shown in FIGS. 5 (a) and 5 (b), the first annular retainer 70 and the second annular retainer 80 are fitted into the inner cylinder 160 whose inner diameter and outer diameter are changed in stages. Supported in the axial direction. Furthermore, when the transfer charge is ignited and combusted by a flame generated by the operation of the first igniter 32 and a combustion product is generated, the rate of increase of the combustion product is increased closer to the top plate 12, and the transfer hole 64 is increased. Since the discharge rate of the combustion products from the first to the first combustion chamber 30 is also increased, the ignitability of the first gas generating agent 31 is improved.

(5) Gas Generator in FIG. 6 The gas generator 1D in FIG. 6 is different from the gas generator 1 in FIG. 1 except that the shapes of the first annular retainer and the second annular retainer are different. Same as 1. Also in the gas generator 1D of FIG. 6, the annular filter 190 shown in FIG. 4 can be used, and the inner cylinder 160 shown in the gas generator 1C of FIGS. 5A and 5B can also be used. .

The first annular retainer 170 includes a first annular bottom surface portion 171 having a plurality of first communication holes 172 penetrating in the thickness direction, a first inner peripheral edge portion, and a first outer peripheral edge portion of the first annular bottom surface portion 171. A first annular inner wall portion 173 and a first annular outer wall portion 174 each extending in the same direction are provided. Furthermore, the front-end | tip part of the 1st annular outer wall part 174 has the 1st flange part 175 extended to the radial direction outer side (1st surrounding wall part 13 side). The first annular bottom surface portion 171 includes a first annular inner bottom surface portion 171a having a first communication hole 172 on the inner cylinder 60 side and a first annular outer bottom surface portion 171b on the first peripheral wall portion 13 side. Between the first annular inner bottom surface portion 171a and the first annular outer bottom surface portion 171b, a first annular step which is inclined toward the top plate 12 from the first annular inner bottom surface portion 171a toward the first annular outer bottom surface portion 171b. A surface 171c is formed.

The second annular retainer 180 includes a second annular bottom surface portion 181 having a plurality of second communication holes 182 penetrating in the thickness direction, a second inner peripheral edge portion, and a second outer peripheral edge portion of the second annular bottom surface portion 181. A second annular inner wall portion 183 and a second annular outer wall portion 184 each extending in the same direction are provided. Further, the distal end portion of the second annular outer wall portion 184 has a second flange portion 185 extended outward in the radial direction (on the first peripheral wall portion 13 side). The second annular bottom surface portion 181 has a second annular inner bottom surface portion 181a having a second communication hole 182 on the inner cylinder 60 side and a second annular outer bottom surface portion 181b on the first peripheral wall portion 13 side. Between the second annular inner bottom surface portion 181a and the second annular outer bottom surface portion 181b, a second annular step surface inclined toward the bottom plate 21 from the second annular inner bottom surface portion 181a toward the second annular outer bottom surface portion 181b. 181c is formed.

The first communication hole 172 and the second communication hole 182 do not overlap in the axis X direction as in the gas generator 1A shown in FIG. 3, but may overlap in the axis X direction.

In the first annular retainer 170 and the second annular retainer 180, the first annular inner bottom surface portion 171a and the second annular inner bottom surface portion 181a face each other in the axis X direction, and the first annular outer bottom surface portion 171b and the second annular outer bottom surface portion. 181b is opposed in the axis X direction, and the first annular step surface 171c and the second annular step surface 181c are opposed in the axis X direction. Therefore, the interval (w1) between the first annular outer bottom surface portion 171b and the second annular outer bottom surface portion 181b is larger than the interval (w2) between the first annular inner bottom surface portion 171a and the second annular inner bottom surface portion 181a. (W1> w2). The annular filter 90 is disposed at a distance (w1) between the first annular outer bottom surface portion 171b and the second annular outer bottom surface portion 181b.

In the embodiment shown in FIG. 6, since the volumes of the first combustion chamber 30 and the second combustion chamber 50 are increased without changing the size of the annular filter 90, the first gas generating agent 31 and the second gas generation are performed. By increasing the filling amount of the agent 51, the amount of gas generation can be increased.

(6) Gas Generator in FIG. 7 The gas generator 1E in FIG. 7 is the same as the gas generator 1 in FIG. 1 except for the shape of the second annular retainer. is there. In the gas generator 1E of FIG. 7, the annular filter 190 shown in FIG. 4 can be used, and the inner cylinder 160 shown in the gas generator 1C of FIGS. 5 (a) and 5 (b) can be used. .

The first annular retainer 70 is the same as the first annular retainer 70 used in the gas generator 1 of FIG. The second annular retainer 280 includes a second annular bottom surface portion 281 having a plurality of second communication holes 282 penetrating in the thickness direction, a second inner peripheral edge portion and a second outer peripheral edge portion of the second annular bottom surface portion 281. A second annular inner wall portion 283 and a second annular outer wall portion 284 each extending in the same direction are provided. Further, the distal end portion of the second annular outer wall portion 284 has a second flange portion 285 extending outward in the radial direction (on the first peripheral wall portion 13 side). The first communication hole 72 and the second communication hole 282 do not overlap in the direction of the axis X when viewed from the first communication hole 72.

The second annular bottom surface portion 281 has a second annular inclined surface portion 281a having a second communication hole 282 on the inner cylinder 60 side and a second annular flat surface portion 281b on the first peripheral wall portion 13 side. The second annular inclined surface portion 281a is inclined toward the bottom plate 21 from the second annular inner wall portion 283 toward the second annular flat surface portion 281b. Therefore, the interval (w1) between the first annular bottom surface portion 71 and the second annular flat surface portion 281b is larger than the interval (w2) between the first annular bottom surface portion 71 and the second annular inclined surface portion 281a (w1>). w2). In addition, the space | interval (w2) of the 1st cyclic | annular bottom face part 71 and the 2nd cyclic | annular inclined surface part 281a is continuously increased toward the 1st surrounding wall part 13 side from the inner cylinder 60 side. The annular filter 90 is disposed at a portion of the interval (w1) between the first annular bottom surface portion 71 and the second annular flat surface portion 281b.

In the embodiment shown in FIG. 7, since the volume of the second combustion chamber 50 is increased without changing the size of the annular filter 90, the amount of gas generated is increased by increasing the filling amount of the second gas generating agent 51. The amount can be increased.

Further, since the second annular inclined surface portion 281a is inclined toward the bottom plate 21 from the second annular inner wall portion 283 toward the second annular flat surface portion 281b, the combustion gas in the first combustion chamber 30 is in the first communication hole 72. When the air enters the plenum chamber 40 and collides with the second annular inclined surface portion 281a, the direction changes in the direction of the annular filter 90 and flows. For this reason, it becomes difficult for the combustion gas to come into contact with the seal tape 87 that closes the second communication hole 82. The second annular inclined surface portion 281a functions in the same manner as the guide plate 77 shown in FIG.

The invention has been described above. Of course, the present invention includes within its scope various modifications, which do not depart from the scope of the present invention. Also, all that would be considered obvious variations of the present invention by those having ordinary skill in the art are within the scope of the claims set forth below.

Claims

A top plate, a bottom plate, and a housing having a peripheral wall portion having a gas discharge port;
A first combustion chamber formed between a first annular retainer disposed in the housing and the top plate;
A second combustion chamber formed between a second annular retainer disposed in the housing and the bottom plate;
A plenum chamber that communicates with the gas outlet disposed between the first combustion chamber and the second combustion chamber;
A first igniter fixed to the bottom plate and configured to ignite and burn the first gas generating agent in the first combustion chamber; and a second igniter disposed in the second combustion chamber, facing the second combustion chamber. A second igniter that ignites and burns,
It is disposed in the housing, the first end opening surrounds the first igniter, the second end opening is located on the top plate side, and a transfer hole is formed at a position facing the first combustion chamber. Having an inner cylinder,
The first annular retainer has a first annular bottom surface portion having a first communication hole, and a first inner peripheral edge portion of the first annular bottom surface portion is brought into contact with a peripheral wall portion of the inner cylinder, and the first communication The first combustion chamber and the plenum chamber communicate with each other through a hole,
The second annular retainer has a second annular bottom surface portion having a second communication hole, a second inner peripheral edge portion of the second annular bottom surface portion is in contact with a peripheral wall portion of the inner cylinder, and the second communication A gas generator in which the second combustion chamber and the plenum chamber are communicated with each other through a hole.
The second communication hole is closed by a closing member from the plenum chamber side;
The gas generator according to claim 1, wherein the first communication hole and the second communication hole are arranged so as not to overlap in the axial direction.
The said 2nd communicating hole is obstruct | occluded with the obstruction | occlusion member from the said plenum chamber side, and is arrange | positioned so that it may not overlap with the said 2nd igniter in an axial direction. Gas generator.
An annular filter is disposed in the plenum chamber;
The first annular end surface of the annular filter is in contact with a portion of the first annular bottom surface portion that does not have the first communication hole, and the second annular end surface is in a portion of the second annular bottom surface portion that does not have the second communication hole. Abutted,
The gas generator according to any one of claims 1 to 3, wherein at least a portion where the first annular bottom surface portion and the second annular bottom surface portion are directly opposed to each other is formed.
In a housing having a top plate, a bottom plate, and a peripheral wall portion having a gas discharge port, a first combustion chamber arranged on the top plate side, a second combustion chamber arranged on the bottom plate side, A plenum chamber facing the gas discharge port disposed between the first combustion chamber and the second combustion chamber;
The bottom plate has a first igniter for igniting and burning the first gas generating agent accommodated in the first combustion chamber, and an ignition for burning the second gas generating agent accommodated in the second combustion chamber. The second igniter is installed,
In the first igniter, the first end opening surrounds the first igniter, the second end opening is located on the top plate side, and is in a position facing the first combustion chamber. Arranged to communicate with the first combustion chamber via an inner cylinder having a hole;
The second igniter is disposed facing the second combustion chamber;
The first annular retainer has a first annular bottom surface portion having a first communication hole, and a first annular outer wall portion extended in the top plate direction from a first outer peripheral edge portion of the first annular bottom surface portion. The first annular retainer is configured such that a first inner peripheral edge of the first annular bottom surface is in contact with a peripheral wall of the inner cylinder, and the first annular outer wall is between the housing peripheral wall. In a state of being spaced apart, the annular end surface in the axial direction of the first annular outer wall portion is fitted into the inner cylinder so as to be in contact with the top plate,
The second annular retainer has a second annular bottom surface portion having a second communication hole, and a second annular outer wall portion extended in the top plate direction from the second outer peripheral edge portion of the second annular bottom surface portion. The second annular retainer is configured such that the second inner peripheral edge of the second annular bottom surface is in contact with the peripheral wall of the inner cylinder, and the second annular outer wall is in contact with the peripheral wall of the housing. Is fitted into the inner cylinder so that
The first combustion chamber comprises a space surrounded by the inner cylinder, the first annular retainer, and the top plate;
The plenum chamber is composed of a space surrounded by the inner cylinder, the first annular retainer, a housing peripheral wall having the gas discharge port, and the second annular retainer;
The gas generator, wherein the second combustion chamber comprises a space surrounded by the inner cylinder, the second annular retainer, the housing peripheral wall portion, and the housing bottom plate.
The housing has a diffuser shell composed of a first peripheral wall portion having a top plate and a gas discharge port, and a closure shell composed of a bottom plate and a second peripheral wall portion,
The outer surface of the second peripheral wall portion of the closure shell is brought into contact with and integrated with the inner surface of the first peripheral wall portion of the diffuser shell, so that the closure shell first facing the top plate side of the diffuser shell. An annular step surface composed of an annular end surface of the two peripheral walls is formed,
The first annular retainer has a first flange portion extending radially outward from a tip end of the first annular outer wall portion, and the first flange portion is in contact with the top plate. ,
The second annular retainer has a second flange portion extending radially outward from a second annular outer wall portion, and the second flange portion is in contact with the annular step surface. The gas generator according to claim 5.
The gas generator according to claim 5 or 6, wherein an inner diameter and an outer diameter of the inner cylinder are reduced from the bottom plate side toward the top plate side.
The inner diameter and outer diameter of the inner cylinder are gradually reduced from the bottom plate side toward the top plate side,
A hole of the first annular retainer is fitted into the first annular step portion closest to the top plate side so as to be prevented from moving to the bottom plate side, and the second closest from the top plate side. The gas generator according to claim 5 or 6, wherein the gas generator is disposed so that movement toward the bottom plate side is prevented by fitting a hole of the second annular retainer into a two annular stepped portion.
A second communication hole of the second annular retainer is closed by a closing member from the plenum chamber side;
The first communication hole of the first annular retainer and the second communication hole of the second annular retainer are arranged so as not to overlap in the axial direction. Gas generator.
5. The second communication hole of the second annular retainer is closed by a closing member from the plenum chamber side and is disposed so as not to overlap the second igniter in the axial direction. The gas generator according to any one of 1 to 8.
An annular filter is disposed in the plenum chamber;
In the annular filter, the first annular end surface on the top plate side is in contact with a portion of the first annular bottom surface portion of the first annular retainer where there is no first communication hole, and the second annular end surface on the bottom plate side is a second annular surface. The retainer is disposed in contact with a portion of the second annular bottom surface of the retainer that does not have the second communication hole, and a part of the outer peripheral surface is disposed in contact with the second annular outer wall. The gas generator according to any one of the above.
An annular filter is disposed in the plenum chamber;
In the annular filter, the first annular end surface on the top plate side has a first annular projection, and the second annular end surface on the bottom plate side has a second annular projection,
The first annular protrusion is brought into contact with a portion of the first annular retainer where the first annular bottom surface portion does not have the first communication hole, and the second annular protrusion is a second communication hole of the second annular bottom surface portion of the second annular retainer. The gas generator according to any one of claims 4 to 10, wherein the gas generator is disposed so as to be in contact with a portion having no air and a part of an outer peripheral surface thereof is in contact with the second annular outer wall portion.
The axial distance between the first annular retainer and the second annular retainer is such that the distance closer to the housing peripheral wall (w1) is larger and the distance closer to the inner cylinder (w2) is smaller (w1). > W2), an annular filter is disposed at a portion where the interval is w1, and the first communication hole and the second communication hole are formed at a portion where the interval is w2. The gas generator according to any one of 10.